In the past decade, we have witnessed tremendous advances in the development and implementation of non- invasive molecular imaging in order to phenotypically characterize cancers through early detection, staging using molecular imaging. Among these techniques, optical and magnetic resonance (MR) imaging modalities have evolved with remarkable speed. This approach has revolutionized the way we detect the diseases in both basic research and clinical applications. Despite its recent success however, experiences obtained from these works has led us to believe that there is no single imaging modality which can effectively provide information that is sufficiently robust to detect small populations of cells through highly sensitive and deep penetration and with the capability of quick data acquisition and processing. Therefore, the current trend in this area attempts to combine the imaging modalities necessary to provide superior imaging properties through synergistic enhancements unmatched by any single modality. In this application, we propose to develop a novel hybrid imaging nanoprobe (HINP) for high resolution imaging of dendritic cells (DCs) using MR-optical imaging techniques. The HINP consists of near-infrared (NIR) emitting semiconductor quantum dots (QDs) tethered to superparamagnetic iron oxide (SPIO) nanoparticles. Further, we plan to modify this hybrid probe to generate a membrane-permeable derivative for tracking the migration of DCs in vivo. In our preliminary experiments, we synthesized a library of QDs with suitable characteristics for in vivo imaging, including water solubility, stability, precisely tunable NIR emissions and high quantum yields (30-70%). The dextran cross-linked negative contrast SPIO nanoparticles have also been developed. Our hypothesis is that, if developed, this hybrid imaging nanoprobe could be used to track the migration patterns of DCs in a mouse model using optical and MR imaging techniques. Additionally, we want to optimize the sensitivity of DCs migration detection via HINP and improve the distribution route of these immunological cells. PUBLIC HEALTH RELEVANCE: Hybrid imaging nanoprobes from semiconductor quantum dots and superparamagnetic iron oxide nanoparticles will be developed for cumulative enhancing both optical and magnetic resonance imaging techniques capabilities. This multimodal imaging strategy will extend our current understanding of cancer biology.